Tilting chair construction



F. LIE 2,991,125

TILTING CHAIR CONSTRUCTION 2 Sheets-Sheet 1 July 4, 1961 Filed March 19, 1958 July 4, 1961 F, |E 2,991,125

TILTING CHAIR CONSTRUCTION Filed March 19, 195e 2 sheets-sheet 2 Ig I I l INVENTOR. F7/,V/V /E United States Patent TILTlNG 'CHAIR CONSTRUCTION Finn Lie, Ring Station, near Hamar, Norway Filed Mar. 19, 1958, Ser. No. 722,530

7 Claims. (Cl. 297-304) vThis invention relates to tilting chair constructions, as for example oice chairs, airplane chairs, bus chairs, railroad coach chairs, and other chairs wherein the seat and back can be tilted with respect to the base structure and with respect to each other.

, Objects of the invention arerto provide a tilting chair construction wherein: Y (1) A pair `of torsion bar assemblies are provided, one for. resiliently opposing rearward tilt lof the chair seat and the other for resiliently opposing'rearward tilt ofthe chair back,

(2) The torsion bar assemblies are so interconnected as'to prevent tilting of` the chair seat except when the occupant leans lagainst the chair back, thereby preventing any sudden tilting of the seat prior to comfortable seating of the occupant. o

` '(3) The torsion bar assemblies occupy very little Vertical space so as to be capable of attachment very near the underside of the seat frame, thereby making the assemblies substantially invisible to viewers of the chair, y

` (4) The chair structure is so constructed as to permit employment of a Huid-operated control structure for setting the chair elements in adjusted positions against the restraining forces of the torsion bar assemblies,` and (5) The various chair-supporting components are so Adesigned and positioned as to permit support of a plurality of chairs in side-by-side relation with minimum parts duplication. Y j Y Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

In the drawings: FIG. 1 is a plan view of one embodiment of the inventration purposes.

lFIG. 2 is a sectional View on line III--II in FIG.

; FIG. 3 is an elevational View of an adjustment structure employed in the FIG. l embodiment.

FIG. 4 is an end elevational View of another embodiment of the invention with seat and back portions removed. j p

FIG. 5 is a view of the complete FIG. 4 embodiment on a reduced scale.

FIG. 6 is a front view of the FIG. 4 embodiment.

Before explaining the present invention indetail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carriedrout in various ways. Also, y

it is to be understood that the phrase'ology or terminology employed herein is for the purpose of description `and .not of limitation. i

In FIG. 1 there is shown a tilting chair construction including a post 11 projecting upwardly from a conventional roller-equipped tripod structure (not' shown). Post 1|1 includes a reduced diameter extension 10 which 4projects through al pair of vertically-aligned openings in a pairlof plates 9. v

t V PlatesU 9` are interconnected by means of two vertical wall elements 8 which `fxedly mount a horizontally elon- 2 base structure vfor supporting tubev 5. ,Rotatably encircling tube 5 are two sleeves 6, 6 xedly carried by respective ones of channels 7, 7. A seat frame 3 is supportably carried on thefchannels, said frame having side portions 2 and rear portions `4. i"

One end of tube 5 anchoringly mounts a plug 12 which in turn tanchoringly mounts the adjacent end of a square cross-sectioned torsion bar 13. Bar 13 extends freely through tube 5 into xed connection With a plug 14 rotatably carried in a sleeve 6. Plug 14 is formed withextension 15 which projects into a notch formed onthe undersurface of nut 16 threadedly received on manually turnable screw 17. Suitable rotation of the `screw is eilifective to turnA extension 15 counterclockwise about the sleeve 6 axis so as to set up a 'resilient force in'bar 13 tending to urge seat frame 3 clockwise about thejsleeve 6 axis. However actual clockwise movement'of frameiS is prevented by pins 22 which project from wallelements 8 into slots 23 in U-shaped bracket 20: Bracket 20 is connected to channels 7 through the mechanism of torsion bar assembly B; bracket 20 is therefore (under normal conditions) fixed with respect to frame 3 so as to cooperate with pins22 in preventing clockwisentilt of -frame 3 from the FIG. 3 position. `V

Torsion bar assembly B includestwo sleeves 6a xedly secured to channels 7 anda tube 5a fixedly secured to bracket 20 as by welding. A torsion bar 13a extends freely within tube .5a from a tube-carried plug (not shown but similar to plug 12) to a sleeve-carried plug 14a having an extension A15a engaged in a notch formed in nut 16.

Bracket 20 xedly carries two arms 19 which extend horizontally past frame 3 and then vertically upward to form a chair back structure. Suitable padding (not shown) may be provided on the upper portion of the vertical portions to insure comfortablel support of the human back. j

The operation of torsion bar assembly B is'isuch as to set up a resilient restraining force tendingv to oppose counterclockwise movement of chair back elementsl19.

Thus, as the Occupant leans his weight against elements 19 tube 5a tends to'rotate counterclockwis'e. 'I'he encircling sleevesra are however connected to seat -frame 3 and one end of torsion bar 13a so as to re'siliently oppose rearward tilt of elements 19. Theadjustlnlent'` of extension 15a by screw 17 determines the magnitude of this opposing force.

During rearward vtilt of seat frame 3 bracket 20 tends to move downwardly about the sleeve 6 axis so as to move slots `23 downwardly relative to pins 22.' lSuch movement would cause .the presetV tension in bar 13a to force arms 19 counterclockwise;however links 21 are provided to prevent such movement of arms 19.

The general operation of the FIG. `1 embodiment is such that torsion bar assembly A (elements 5,6 and 13) acts .toresilientl'y cushion rearward tilt of the 'clia'ir seat against the oocupants rearward shifting/of hi'siweight. However rearward tilt of the chair seat is prevented until after the occupant leans back against elements 19;` in this manner the occupant does notl experience any. sudden .unexpected tilting of the chair seat while he` is .leaning -forward in the chair. The protection against unexpected seat tilt is achieved through the provision' ofr linksr21. Thus, counterclockwise tilt of frame 3 about the sleeve-6 axis must be accompanied by a corresponding downward shift ofv assembly B about the sleeve 6axis; Suchsshift cannot take place because oflinks 21. However, .when arms 19 are forced downwardly (by the occupants weight against the chair back) the seat is automatically drawn downward. In this manner a comparatively. small leaning force on the chair back is elective to tilt both the back `and seat.

In connection -with the seat tilt preventing action of links 21, it will be seen that links 21 prevent the seat from tilting until after the links have begun moving under the force of back elementsf19. Thus, in the FIG. 2 position a downward force on frame 3 is ineffective to `tilt the frame about the axis of bar 13 because links 21 would have to pivot about their4 connections with base structure .'8. The theoretical arc of the links around base structure 8 is inconsistent with the arc of the links due to pivoting of frame 3 around the axis of bar 13; hence links 21 act as jamming devices for preventing any tilting of frame 3.

However, when a counterclockwise force is applied to the back structure, elements 19 and bracket 20 are free to pivot about the upper pivots of the links and the axis of bar 13. In this manner the links are drawn slightly counterclockwise to enable seat frame 3 to gradually tilt rearwardly.

The FIG. 4 embodiment includes a base structure 25 comprising front and rear leg elements xedly secured to tube 5. As shown in FIG. 6 tube 5 may extend laterally beneath a plurality of chair units so as to provide resilient restraining forces therefore with minimum parts duplication. The FIG. 4 unit carries torsion bar assemblies of the type shown at A and B in FIG. 1.

In the FIG. 4 embodiment sleeves 6, 6 are carried beneath chair seat 32. The chair backs 33 are movably carried for tilting movements by means of two arms 19, each having ears for receiving a cross pin 30. Pin 30 pivotally suppots rod 29 of a fluid cylinder dashpot unit 26. Cylinder 27 of the unit is pivotally carried on rear legs 25 by means of a pivot pin 28.

Rod 29 carries a piston within cylinder 27. Opposite ends of the cylinder are ported to a uid line (not shown) which leads through a valve openable and closable by manually-actuable push button 31 carried in chair arm 34.

Cylinder unit 26 functions to lock seat 32 and back 33 in adjusted positions. In operation, when the valve is open and the occupant leans against back 33 rod 29 is moved downwardly into cylinder 27 so as to force oil or other uid from beneath the piston, through the line and valve, and into the portion of cylinder 27 above the piston. When the valve is closed by push button 31 the ow from beneath the piston is halted so as to prevent any further downward movement of rod 29. Upward movement of rod 29 is prevented by the oil trapped above the piston. When the valve is again opened the trapped oil is permitted to flow from above the piston under the force of the torsion bar assemblies. It will thus be seen that unit 26 is effective to releasably hold the chair in any desired positions of adjustment.

The general mode of operation of t-he FIG. 4 embodiment is similar to that of the FIG. 1 embodiment except that dashpot unit 2-6 performs the stopping function of pins 22 as well as the adjustable locking function previously described.

I claim:

1. A tilting chair construction comprising a base structure; a seat structure; a irst torsion bar assembly between the base structure and seat structure for setting up a resilient restraining force opposing rearward tilt of said structure; a back structure; a second torsion bar assembly between the seat structure and back structure for setting up a resilient restraining force opposing rearward tilt of said back structure; and means interconnecting said torsion bar assemblies preventing the rst torsion bar assembly from yielding until a back-tilting force has been appliedto the second torsion bar assembly.

k2. A, tilting chair constructionV comprising a base structure; a seat structure; a rst torsion bar assembly between the base structure and seat structure for setting up a resilient restraining force opposing rearward tilt of said seat structure; a back structure; a second torsion bar assembly connected with the back structure for setting up a resilient restraining force opposing rearward tilt of said back structure; movable mechanism between the back structure and first torsion bar assembly locking said iirst assembly against yielding movement; and structure carried by the back structure for rendering the locking mechanism inoperative in response to tilting movement of the back structure.

3. A tilting chair construction comprising a base structure; `a seat structure pivotally mounted for tilting movement around a rst horizontal axis relative to the base structure; rst resilient restraining means between said base structure and seat structure opposing rearward tilt of said seat structure; a back structure tiltably mounted on a portion of the seat structure for tilting movement about a second axis; second resilient restraining means connected between the back structure and seat structure opposing rearward tilt of said back structure; and link means having pivotal connections between the base structure and back structure for preventing the seat structure from tilting about the lirst axis until the back structure has begun its tilting movement about the second axis.

4. A tilting chair construction comprising a centrally disposed base structure; a seat structure; Ia first torsion bar assembly between the base structure and a forward portion of the seat structure for setting up a resilient restraining force opposing rearward tilt of said seat structure; a back structure; -a second torsion bar assembly between a rear portion of the seat structure and the back structure for setting up a resilient restraining force opposing rearward tilt of said back structure; and link means between the base structure and the forward end portions of the back structure for preventing the rst torsion bar `assembly from yielding until after the back structure has begun its tilting movement.

5. A tilting chair construction comprising a base structure; a seat structure tiltable about a first axis; Ia iirst resilient restraining means ybetween the base structure and seat structure opposing rearward tilt of said seat structure; a back structure tiltable about a second axis; second resilient restraining means between the seat structure and back structure opposing rearward tilt of said back structure; and link means connected between the base structure and back structure, the spacing `between the iirst axis and link means-back structure connection being greater than the spacing between the link means-base structure connection and link means-back structure connection to prevent the seat structure from tilting until the back structure has begun its tilting movement.

6. A tilting chair construction comprising a base structure; a seat structure comprising a pair of spaced parallel Aforwardly extending mounting bars; a rst torsion bar assembly extending between the mounting bars `and connected at an intermediate point with said base structure for setting -up a resilient force opposing rearward tilt of said seat structure; a chair back structure; and a second torsion bar assembly extending between the mounting bars and connected yat `an intermediate point with the back structure for setting up a resilient restraining force opposing rearward tilt of said back structure.

7. A tilting chair construction comprising a base structure; a seat structure tiltably mounted with respect to the base structure; resilient restraining means between said base structure and seat structure for opposing rearward tilt of said seat structure; a tiltable chair back structu-re including arm elements extending generally horizontally 4beneath and into supported connection with the seat structure; resilient restraining means opposing tilt of said back structure; and uid dashpot means trained References Cited in the le of this patent UNITED STATES PATENTS Herold July 25, 1939 Herold June 8, 1943 6 Boemr Apr. 9, 1946 Sheldick et al July 2, 1946 Morris et al Feb. 17, 1953 Paquin Mar. 10, 1953. Lie Sept. 20, 1955 Lie Aug. 28, 1956 

